jdohio1959

I have a 66 big block that I'm almost finished with the off-body restoration, and I want to covert the brake system to a dual master cylinder. I've reviewed many kits out there and would like to know if I can splice the rear line into my original line currently on the car? I reason I'm asking is that I have brand-new stainless-steel brake lines on the car and really don't want to replace them if I don't have too.

R66

I put a dual master cylinder on R66. I used the original lines to front and rear. I disconnected the rear line (3/16") from the distribution block and plugged that inlet. Then used a coupling to couple a new line from the rear of the new dual master cylinder. The original line from the single master cylinder is connected to the front port on the new dual master cylinder. You will need an adapter to fit the original line to the new master cylinder port.
Not a BB, but brakes work fine. NOTE: this is not with a power booster although I don't think it would make a difference.

rayL79

I also did it on my 66 and posted a parts list (flare adapters and a plug) a few years ago. You don't need a kit...just a 67 master cylinder.
Ray

silver837

And a considerable amount of cash .

jdohio1959

Ray,
Could you please forward me your post with this list?
Regads,
Jim

jdohio1959

Ray,

Never mind about my earlier post, I found your post. Were your lines original? I have stainless steel line and not sure how easy they will be to re-bend? Any ideas?

Regard,

Jim

Factoid

I did this two years ago. Currently, your rear line connects into a four port brass block on the frame inboard of the driver side front wheel. The rear line is almost a perfect length to bend to the new dual MC. Given your lines are SS you should remove the clutch z-bar and use a tubing bender to relocate the rear line without kinking it. This will be the hardest part of your project and it’s not that difficult. Then replace the brass block with the correct three port block (I also replaced the front line from the MC to the brass block. Good luck!


You will also need the intake manifold fitting for the vacuum line to the booster, vacuum hose, bracket for the brake pedal brake light switch activator, and new rubber pedal cover.

jdohio1959

Ray,
Did you have to use the proportioning valve to fit the original lines?

Regard,

Jim

rayL79

That's not a proportioning valve on the 67's...it's an electrical switch that makes contact if there is a pressure imbalance between the front and rear brakes.. It turns on the red "BRAKE" dashboard light. 66's don;t have it and you don't need it.
Ray